Hong Kong travellers to Tibet have been advised to take precautions against pneumonic plague, a highly contagious bacterial infection. The Centre for Health Protection issued the advisory yesterday after it learned of two fatal cases in Linzhi. A 35-year-old man and his wife, 38, who were not from Hong Kong, died last month. Travel Industry Council executive director Joseph Tung Yao-chung said he was not aware of any Hong Kong tours in Linzhi.